An organic EL illumination panel using light emission from organic electroluminescence (organic EL) is formed by laminating a transparent electrode layer, an organic EL layer and an electrode layer sequentially onto a transparent substrate and sealing them with a sealing material. Since a substrate used in such an organic EL illumination panel is required to have stiffness and transparency ensuring high transmission to light emitting from organic EL, glass substrates have been used. However, such glass substrates are brittle, is not easy to handle, and is difficult to make a glass substrate having a thickness such as a thin film. As such an organic EL illumination panel requires miniaturization, slimming, light weight and flexibility, transparent and flexible resin film attracts attention as an alternative to glass substrate since they are capable of winding as a roll, is easy to handle, is able to manufacture organic EL efficiently, has an improved design properties, and is inexpensive.
As shown in FIG. 7, an organic EL illumination panel has a structure that a transparent electrode layer (12), an organic layer (13) and an electrode layer (14) are sequentially laminated onto a transparent substrate (11) followed by fixing a sealing material (15) to the transparent substrate (11) via an adhesive (17) of a seal part (16), and a total thickness is about several mm To obtain a flexible organic EL illumination panel, a transparent and flexible resin film is used for the transparent substrate (11) and also a material having the same flexibility as the substrate is used for the sealing material (15), so that bending property and ductility are consistent between the substrate and the sealing material. However, when the organic EL illumination panel is bent, as shown in FIG. 8, the organic layer (13) having a highly thin thickness of nm order or the electrode layer (14) may be damaged due to contact and compression with the sealing material (15).
As an example of organic EL elements, it has been reported an organic EL element that spacer layers are provided in regions having no electrode layer on a substrate to fill gaps, and an organic material layer is provided thereon, thereby suppressing the permeation of air into the gaps, the deterioration of the organic EL element due to moisture present in air, and the diminishment of luminous brightness due to damage caused by bending of the organic material layer (Patent document 1), or an organic EL element panel that a sealing material having no spacer is used in regions with multi-level crossing of wirings so as to suppress electrical contact between an upper wiring and a lower wiring even if spacers are inserted under excess sealing pressure (Patent document 2).
Besides, it has been reported an organic EL element comprising a pixel electrode, a counter electrode, an organic light-emitting layer therebetween, a mask spacer on a partition wall surrounding the pixel electrode and an inorganic film on the partition wall so as to suppress to stick material of an auxiliary counter electrode to the mask spacer and peel when forming the auxiliary counter electrode by vapor deposition and an organic EL device using the organic EL element which is able to suppress to occur defects of emission (Patent documents 3 and 4).
In the field of such organic EL illumination panels, there is a need for an organic EL illumination panel which is sealed between a substrate and a sealing material made of a flexible substrate and be able to suppress the occurrence of defects in an organic layer containing organic EL or an electrode layer even when bending force is applied to an organic EL illumination panel.